@slicemedia/devkit-core

@slicemedia/devkit-core

Side-effect-free addon lifecycle, event, DOM, breakpoint, viewport, asset, and CSS utilities for Webflow browser code.

Install the current release candidate through the npm next tag:

npm install @slicemedia/devkit-core@next
pnpm add @slicemedia/devkit-core@next
yarn add @slicemedia/devkit-core@next

defineAddon() declares serializable metadata and lifecycle hooks. createAddon() returns an inert instance with init, refresh, destroy, setOptions, getState, and on. Consumer projects decide what to initialize and bundle. Importing the package never registers a global; the queue and duplicate-version runtime is available only through an explicit installDevKitRuntime() call and no standalone global build is shipped.

Opt-in observeViewportEntryOnce, observeElementVisibility, and createLayoutRefreshGuard support deferred work, visibility-based animation control, and refreshes after late layout changes. The guard supports optional window-load settling passes and reason/count diagnostics. loadSharedModule() and registerSharedModule() share project vendor APIs across independent addon bundles; loadAssetOnce() shares pending loads and security checks per document. See shared dependencies. An explicitly installed window runtime exposes cancellable whenReady(name, callback) subscribers; registered APIs are available directly as window.slicemediaDevKit.counter, for example. Addon instances emit named init, refresh, and destroy completion events alongside status, options, error, and authored custom events. The existing ready promise still waits for its queue. See runtime helpers.

The separate optional @slicemedia/devtools package provides createDevTools() and inspectDevKit(): an on-page addon inspector and a read-only attribute audit. Core does not install or bundle it. See the DevTools guide for standalone setup, staging activation, console opt-in on production, saved window preferences, and scoped markup contracts.

Support and security

See Slice Media's support policy for help and maintenance expectations. Report vulnerabilities through the DevKit security policy, not a public issue.

Project notice

Licensed under MIT. This package is independently developed by Slice Media and is not affiliated with, endorsed by, or sponsored by Webflow, Inc. Webflow and related marks belong to their respective owners. AI tools materially assisted its implementation and documentation; production use still requires human review, accessibility and security checks, and project-specific testing.

The inspection API exposes conditional markup requirements, shared per-root option resolution, and read-only diagnostics. initializeAddon(runtime, instance) keeps failed startup visible to inspection while preserving public API readiness. The side-effect-free @slicemedia/devkit-core/inspection entry exposes contract validation and resolution helpers for independent inspectors. The separate DevTools package owns the standalone browser artifact; see production inclusion.